Epstein-Barr virus (EBV) is associated with two human tumors, Burkitt's lymphoma and nasopharyngeal carcinoma. In addition, reactivation of EBV infection in immunodeficient patients leads to a fatal lymphoproliferative disease. In vitro infection of B lymphocytes with EBV leads to a T-cell independent polyclonal activation and transformation of a smaller fraction of the infected cells. Although the molecular events underlying the processes of infection, transformation, and polyclonal activation are still unknown, the first step involves the interaction of the virus with a specific receptor in the cell membrane. Our long-term goal is to understand the effects of viral binding on subsequent cellular events. In pursuit of this, we have been developing methods for the isolation of the EBV binding component (EBVR) found on Raji human lymphoblastoid cells. We have extracted and partially purified the EBVR from Raji cells and an antibody specific for the receptor. We have significantly improved the purity of EBV virion preparations and are characterizing the virion-associated protein kinase. We are continuing our purification of the EBVR using its affinity for the EBV membrane antigen and will collaborate with Drs. Tedder and Fearon in determining the relationship of the EBVR to the complement CR2 receptor. We are initiating studies to identify viral transcripts and promoters utilized during superinfection of Raji cells. The data obtained should help to elucidate the role of the EBVR in viral infection, transformation, and triggering cells to immunoglobulin production. (MI)